Uttarakhand floods 2021: What, when, and why

Credit: The Hindu

In Uttarakhand, another flood ravages its people in a manner very reminiscent of the devastating 2018 floods. We take you through it, step by step.

Highlights
  • Death toll reaches 67, tentatively 137 still missing
  • 13 villages cut off from roads, with bridges swept away
  • Team of scientists on their way to study cause of  flooding

By Anushka Jain

New Delhi, 21 Feb: The Nanda Devi-Alaknanda rivers flooding has claimed 67 lives so far according to a statement today by Swati Bhadauria, district magistrate of Chamoli district, Uttarakhand.

Graphic showing the sites of two of the fallen bridges Credit: NRSC

The flooding occurred in the ecologically sensitive area of the Rishiganga valley due to as of now unascertained reasons in the Tapovan-Reni area of Uttarakhand, leading to the overflowing of the two rivers. The surge of water  led to the Rishiganga power project, 5 bridges and multiple nearby homes being swept away while downstream the Tapovan-Vishnugad hydel project was also damaged. According to eyewitnesses, water rose 50 to 70 feet because of the flood.

Hours after the incident, CM Trivendra Singh Rawat announced a compensation of Rs 4 lakh for kin of the deceased while a rescue team comprising the Indo-Tibetan Border Police, State and National Disaster Relief Force was dispatched to affected areas. According to a briefing by Union Home Minister to Parliament in Rajya Sabha on 9 February, 197 people had gone missing due to the disaster. “Rescue operation to evacuate these persons is going on a war footing and all-out efforts are simultaneously being made to search for the missing persons,” he said

The Rescue Operations

With 5 bridges being swept away, at least 13 villages were also cut off from access to food, water and electricity. CM Rawat visited two of these villages two days after the incident, promising all relief possible. Food packets were distributed to them by rescue team officials by helicopters, suspension bridges and ziplines according to Indian Express reports.

ALSO READ: Uttarakhand disaster makes Lahaul wary, residents say will oppose hydel projects

Many of these villages are situated near the China border and according to sources were easy to connect with because of existing army presence. “Usually the Army and ITBP personnel descent to Malari village during this time but this year they have remained near the border. This has meant better coordination,” said Navneet Singh, SRDF commandant to the Indian Express.

On Friday news emerged that an early warning water-level sensor was installed at Raini village following the incident, bringing much psychological relief to villagers according to Bhawan Rana, the pradhan of Raini Chak Subhai village. While some of the villagers died due to the floods, some are also suspected to be buried at the NTPC Tapovan Vishnugad tunnel where a few villagers did work.

Part of the ITBP–NRDF rescue forces are being focused thus on the 1,900m Tapovan Tunnel where atleast 35 workers are expected to be buried, as water and debris partially block its entrance. While up to 162 metres of the tunnel has been accessed by the rescuing forces, now exactly 2 weeks after the tragedy there is little hope of finding anybody alive.

Rescue attempts had also been paused in-between due to fear of another series of floods. Machinery, aerial surveys via helicopters, and drone cameras are being used in attempts to clear the affected areas.

Reasons

While initial speculation pointed to a Glacier Lake Outburst Flood that takes place when a glacial lake breaches leading to downstream flooding, however that may not be the case as no information was yet known about any such lakes being present in the Tapovan-reni region. Argha Banerjee, a glaciologist who works at the Indian Institute of Science Education and Research (IISER), Pune says that it might be that a glacier lake was present in the area but not known to scientists.

Bannerjee also has another theory that the lake was formed of completely different causes. “It is possible that an avalanche or a landslide created an obstruction in the flow of the river or streams in the upper mountains, resulting in a makeshift dam-like situation. When the pressure of the flowing water became large, the dam probably gave away, leading to a sudden gush of water. These are just the possible scenarios. We would know the exact reason only after reaching the site. It might take a day or two,” he said.

New satellite imagery is also making the rounds suggesting that it may have been caused by a landslide or avalanche.

Navy divers however reached a glacial lake formed 5 kms from the impacted Raini village today, to measure its depth following the disaster. As ITBP officials a little downstream clear debris and other obstructions from the route, a team of 14 scientists and rescue officials are also on their way to investigate the cause of the disaster.

Too Long,Didn’t Read?